Apparatus for impregnating corrugated cardboard

ABSTRACT

Apparatus for impregnating longitudinally travelling corrugated board having transversely extending flutes, including suction means arranged adjacent one longitudinal edge of the board for establishing a vacuum in the flutes to draw a material, such as an impregnant, therethrough. The invention is characterized by the provision of retaining means for preventing undesirable lateral displacement of the board in the direction of the suction means. In the preferred embodiment, the retaining means comprise longitudinally extending endless belt means responsive to the vacuum established in the flutes for clamping the moving board against lateral displacement without crushing the flutes or causing damage to the board. Preferably the endless belt means are provided with longitudinal ribs that extend within corresponding grooves in the rollers upon which the belts are mounted, thereby preventing lateral movement of the belt meansand the board-relative to the rollers. In accordance with an important feature of the invention, flow control means are provided for accurately controlling the speed and/or extent of longitudinal penetration of the material through the flutes.

tates atent Hoelzinger et al. I

[ 51 June 13, 1972 CORRUGATED CARDBOARD [72] lnventorsz Walther J.Hoelzinger; Johann Wenninger; Walter Mayer; Karl Zoegernltz; HermannSchroetter; Werner Braun, all of Vienna, Austria [73] Assignee: BoiseCascade Corporation, Boise, Idaho [22] Filed: Feb. 9, 1970 [21] App].No.: 9,581

[52] US. Cl ..1l8/39, 118/50, 118/65, v 118/326, 156/210 [51] Int. Cl...B05b 15/04, B31f 1/20 [58] Field of Search ..118/39, 49,50, 64, 65,302, 118/324, 326; 156/210, 473; 239/138 5 6] References Cited UNITEDSTATES PATENTS 1,592,824 7/1926 1,880,065 9/1932' 2,191,827 2/19402,324,787 7/l943 2,698,260 12/1954 2,826,236 3/1958 2,955,330 10/19603,343,977 9/1967 ...118/326 X 3,389,437 6/1968 Andreani ..19/252 FOREIGNPATENTS OR APPLICATIONS 390,462 7/1908 France ..239/1 38 PrimaryEraminer-Mervin Stein Attorney-Lawrence E. Laubscher [5 7] ABSTRACTApparatus for impregnating longitudinally travelling corrugated boardhaving transversely extending flutes, including suction means arrangedadjacent one longitudinal edge of the board for establishing a vacuum inthe flutes to draw a material, such as an impregnant, therethrough. Theinvention is characterized by the provision of retaining means forpreventing undesirable lateral displacement of the board in thedirection of thesuction means. In the preferred embodiment, theretaining means comprise longitudinally extending endless belt meansresponsive to the vacuum established in the flutes for clamping themoving board against lateral displacement without crushing the flutes orcausing damage to the board. Preferably the endless belt means areprovided with longitudinal ribs that extend within corresponding groovesin the rollers upon which the belts are mounted, thereby preventinglateral movement of the belt means-and the board--relative to therollers. In accordance with an important feature of the invention, flowcontrol means are provided for accurately controlling the speed and/orextent of longitudinal penetration of the-material through the flutes.

21 Claims, 17 Drawing Figures PATENTEBJuu 13 I972 3,669,064

SHEET 1 or 6 4 1 6 w 3 m r N. NE 1 INVENTORS Walther J. HoelzingerJohann Wenninger Walter Mayer Karl Zoegernitz Hermann SchroeHer ATTORNEYWerner Brclun Supply PATENTEUJuu 13 m2 Ho? Wax SHEET 8 0F 6 S p y Fig./5

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v Exchanger Means Hot Wax 1NVENTOR5 fdmm ATTORNEY APPARATUS FORIMPREGNATING CORRUGATED CARDBOARD In the patented prior art, variousstatic and dynamic methods and apparatus have been proposed forimpregnating corrugated board with a material having waterproofing,structurally reinforcing, or other characteristic. For example, thedipping of corrugated board in an impregnating bath is disclosed inthe'Wilkins US. Pat. No. 3,402,068, among others. In the Russell et al.U.S. Pat. No. 3,310,363, it is proposed to pass horizontally arrangedcorrugated board through a pres surized impregnating chamber, and in thepatents to Gjesdal US. Pat. No. 3,343,977 and Fairchild US; Pat. No.1,592,824, the precut corrugated board'is arranged vertically about itslongitudinal edge to effect downward flow, by gravity, of the impregnantthrough the vertical flutes (with or without the aid of pressurespraying and/or suction).

From a practical standpoint, it is desirable to impregnate thecorrugated board as it is actually being formed from paper rolls byconventional corrugator equipment. In the prior U.S. patent applicationSer. No. 763,268 filed Sept. 27, 1968, in the names of Werner Achermannet al. (and assigned to the same assignee as the present invention), itwas proposed to impregnate longitudinally travelling horizontallyarranged board by the use of vacuum or suction means that draw theimpregnating materialthrough the transversely arranged flutes of theboard. Owing to the relatively high linear velocity production rates ofthe board (which are on the order of 300 feet perminute or more), it israther difficult to accurately impregnate the board with an exactquantity of impregnant materialper foot of board. This relatively highvelocity rules out the majority of the previously proposed impregnatingmethods and apparatus, leaving the vacuum or suction impregnationconcept as the most feasible process for commercial utilization anddevelopment. I

'A second major consideration in the development of the impregnationequipment is the adaptability of the apparatus for installation on,existing corrugator systems. In practice, the preferred location oftheimpregnating equipment in an existing corrugator system is the ratherlimited space between the order cut-off shear (which is operated onlyperiodically at the end of a given order run) and the Triplex means forlongitudinally scoring and slitting the board. Since the space betweenthese two units is normally rather limited (on the order of 10 to 12feet, for example), another critical design limitation is imposed on theimpregnating equipment which, together with the high linear velocity ofthe board, further impairs the impregnation process. More particularly,in order to draw the impregnating material completely through the flutesduring the relatively short time that the travelling board is within theimpregnating station, a rather high vacuum must necessarily beestablished within the flutes. This high vacuum would normally tend tocause the travelling board to be drawn laterally toward the suctionmeans arranged adjacent one longitudinal edge of the board, with theundesirable result that the ends of the flutes would be closed toprevent air or impregnant materia] from being drawn therethrough.Moreover, the lateral displacement of the board would produceundesirable skewing, buckling or jamming of the board as it is conveyedtoward the Triplex scoring and slitting means.

Another important consideration is the problem of supplying theimpregnatingmaterial to the flutes with such a consistency that theimpregnant will be so drawn through the flutes as to effect uniformimpregnation completely across the board without the quantity of theimpregnant being uneconomically excessive. Thus, in the case of a hotwax impregnant, it is desirable to accurately control theimpregnantto-air ratio, so that the cost of the wax will be reduced, andthe outer surfaces of the liners will have a desired surface condition.In this regard, by appropriate control of the impregnant, a totallyimpregnated board condition may be achieved, or in the alternative, byreducing the wax supply, the outer surfaces of the. liners maybemaintained wax-free for printing and/or gluing, or for coating with inksor other materials. Accordingly, it is necessary to provide a reliablecontrol means for regulating the flow of the impregnating material intothe transporting air stream.

Finally, in order to retard the outward wicking of the wax and to reducethe heat of the corrugated board and thereby facilitate handling at thetake-off station, it is desirable to apply to the upper and/or lowersurfaces of the board a temporary coating of water, ink or other wickingretardant, by spraying in the form of a mist, by sponging, or the like.On the other hand, for achieving acceptable impregnation of thelongitudinal edge portion of the board adjacent the suction means,sufficient impregnating material must be introduced into the flutes touniformly cover the interior of the board throughout its width, takinginto account the inherent increase in the velocity of the impregnant orother material as it approaches the suction ends of the flutes. With theabove and other considerations in mind, the present invention wasdeveloped to provide an improved board impregnating apparatus thatavoids the drawbacks of the known impregnating equipment. The primaryobject of the present invention is to provide improved apparatus forimpregnating corrugated board as it is actually being manufactured onconventional corrugator apparatus, including an impregnating station ofminimum length adapted for insertion subsequent to the heating andcooling stations of the corrugator, and preferably between the ordercut-off shear means and the Triplex scoring and slitting means. Theimpregnating station includes impregnant supply means for supplyingimpregnant material adjacent one longitudinal edge of the board, andsuction means adjacent the other longitudinal edge for establishing avacuum within the flutes to draw the impregnant therethrough. Thepresentinvention is characterized by the provision of retaining meansfor preventing the travelling high speed board from being drawnlaterally 0E line in the direction of'the suction means by the highvacuum established in the flutes.

A more specific object of the invention is to provide vacuum-responsiveclamping means for clamping the travelling board to a stationary framearranged transversely between the impregnant supply and the suctionmeans, use being made of longitudinally extending endless belt meansdriven at the same or slightly greater linear velocity as the board.Preferably the frame is mounted for displacement from the operativeimpregnating position to an inoperative storage or servicing positionwhen not in use. In order to prevent lateral displacement of the endlessbelt means relative to the rollers upon which they are mounted, the beltmeans are provided with longitudinal ribs that extend withincorresponding grooves contained in the rollers. In accordance with animportant feature of the invention, means are provided for accuratelyadjusting the angles of the roller axes relative to the frame to furtherprevent the board from becoming laterally displaced from or skewedrelative to its longitudinal axis of travel.

A further object of the invention is to provide impregnating apparatusincluding means for laterally adjusting the impregnant supply means andthe suction means relative to the longitudinal edges of the corrugatedboard, thereby to accommodate board of different widths. In oneembodiment, the impregnant supply means and the suction means includechannel members connected for lateral adjustment relative to the frame.In a second embodiment, the impregnant supply means is combined with aheat exchanger arranged for lateral adjustment adjacent one edge of theboard, and the suction means is combined with impregnant separator meansarranged for lateral adjustment adjacent the other edge of the board.

Another object of the present invention is to provide impregnant supplymeans including a channel member arranged longitudinally adjacent oneedge of the travelling board and including a series of longitudinallyspaced first outlets for supplying, via adjustable flow control means,an impregnant of desired consistancy adjacent one end of the flutes, anda subsequent second series of second outlets for supplying to theflutes, via adjustable flow control means, hot air or other agent.Furthermore, the suction means includes a similar channel memberarranged at the other longitudinal edge, said suction channel containinga series of suction inlets connected, via adjustable flow regulatingmeans, with a vacuum source. In the case of a wax impregnant, heatingmeans are provided to assure an even distribution of the materialthroughout the lengths of the flutes. By appropriate control of thevarious regulating means (including valve adjustment, nozzleconfiguration and/or dimensions, supply pressures and the like), properuniform impregnation of the flutes throughout their length may beachieved in a positive manner.

Other objects and advantages of the invention will become apparent froma study of the following specification when viewed in the light of theaccompanying drawing, in which:

FIG. 1 is a diagrammatic view of the installation of the impregnationapparatus of the present invention in a conventional corrugator system;

FIG. 1a is a detailed sectional view of a single-wall or double-facedcorrugated board embodiment produced by the system of FIG. 1; I

FIG. 2 is a top plan view of the impregnation station of FIG.

FIGS. 3 and 4 are sectional views taken along lines 33 and 44,respectively, of FIG. 2;

FIG. 5 is a detailed sectional view taken along line 5-5 of FIG. 4;

FIG. 6 is a detailed end view of the roller adjusting means of FIG. 5;

FIG. 7 is a detailed top plan view of the impregnating supply and thesuction means, with the endless belt retaining means removed forclarity;

FIGS. 8-10 are sectional views taken along lines 88, 9-9 and 10-10,respectively, in FIG. 7;

FIG, 11 is a detailed plan view of the impregnation sections of theimpregnant supply channel means of FIG. 7;

FIG. 12 is a detailed view of the impregnant flow regulating means ofFIG. 11;

FIG. 13 illustrates diagrammatically a second embodiment of theinvention wherein the impregnant supply means and the suction means arearranged for movement independent of the retaining means frame;

FIG. 14 illustrates diagrammatically a wax curtain impregnant supplymodification; and

FIGS. 15 and 16 are modifications of the means for mixing the impregnantmaterial with the transporting air to effect a desired impregnant-to-airratio.

Referring first to FIGS. 1 and 1a, the conventional corrugator apparatusincludes a plurality of single facer units 2, 4 and 6 and a roll stand 8for supplying material to the double facer 10 via the preheater l2 andthe glue station 14. In the illustrated system for producing thecorrugated board of FIG. la, the single facers 4 and 6 are temporarilydisconnected reserves, and the single facer 2 forms from paper rolls thelaminate including the fibrous layer 2a with serpentine layer 2b securedthereto. The roll stand 8 provides the bottom surface layer 8a, all ofsaid layers being pressed together for permanent adhesive connection bythe double facer 10. The corrugated board 16 then passes successivelythrough the heating and cooling sections 18 and 20, the intermittentlyoperable order cut-off shear 22, the Triplex longitudinal slitting andscoring means 24, the rotary cut-off means 26, and the severed sectiontake-off means 28. As is conventional in the art, all of theaforementioned corrugator components are driven in synchronism.

In accordance with the present invention, there is provided in thelimited space between the order cut-off shear 22 and the Triplexslitter-scorer 24 an impregnating station for impregnating the traverseflutes of the longitudinally travelling horizontally arranged board witha suitable impregnant material affording waterproofing, fireproofing,structural reinforcing, odorizing, insulating, or other characteristic,such as bitumen, paraffin, waterglass, synthetic plastic resin, glue,paraffinbitumenized emulsion, artificial resin wax mixture, liquidsynthetic materials, synthetic plastic foaming materials,

artificial resins, silicon, sodium silicate solution, alkali metalsilicate, vinyl resin, and the like. Impregnant supply means 32 areprovided for supplying the impregnant adjacent one longitudinal edge ofthe board, and suction means including a wax separator 34 and vacuumpump means 36 are provided adjacent the other edge for establishing avacuum in the transverse flutes to draw the impregnant materialcompletely therethrough.

Referring now more particularly to FIGS. 24, the impregnating stationincludes a frame 40 having at each end a pin 42 that extends from endplate 43 within a corresponding vertical guide slot in the stationaryvertical pillars 44. At its lower end the frame is supported by thecooperation between foot rollers 46 and stationary cam support means 48,the frame being displaceable from the illustrated operative position toan elevated inoperable storage or servicing position illustrated inphantom in FIG. 4. The end plates 43 are rigidly connected by transverseframe cross members 50.

Journalled at each end in bearing means supported by the frame endplates 43 are a pair of upper rollers 52, 54 that support thelongitudinally extending upper endless belt 56 with its lower runadjacent the upper surface of the board 16. Similarly journalled at eachend in the frame are lower rollers 60, 62 and 64 that support thelongitudinally extending lower endless belt 66 with its horizontal upperrun adjacent the lower surface of the board. The upper and lower beltshave such a width relative to the width of the board that when thevacuum is established within the board flutes as will be described ingreater detail below, the upper and lower belts are drawn together bysuction to tightly clamp the board 16 therebetween, whereby lateraldisplacement of the board relative to the frame is positively prevented.As shown in FIGS. 2 and 3, the widths of the endless belts are less thanthe width of the board. In order to prevent lateral displacement of theendless belts relative to the rollers, the belts are provided on theirinner surfaces with continuous longitudinal rib portions 56a and 66a,respectively, that are received in corresponding grooves contained inthe rollers, as shown in FIG. 5. While in the illustrated embodiment,the use of V-belt ribs has been described, it will be apparent to thoseskilled in the art that other retaining means, such as guide rolls, canbe used equally well.

As shown in FIG. 4, the lower endless belt 66 is driven by the maincorrugator drive means 30 via reduction gearing means 70 and sprocketchain 72, the linear speed of the horizontal upper run of the lower belt66 being equal to or slightly greater than the linear velocity of theboard. In accordance with an important feature of the invention, therollers are provided with accurate adjusting means for causing the axesof the rollers to be exactly horizontal and normal to the longitudinalaxis of the board, whereby skewing of the board during passage throughthe impregnating station is avoided. Referring to FIG. 6, it will beseen that longitudinal adjustment of the bearing pedestal 76 within theframe slide 78 is effected by the screw means 80, while longitudinaladjustment of the upper roll pedestal 82 in the bearing slide 84 iseffected by the screw means 86. Vertical adjustment of each end of theupper roll is controlled by the upper screw adjusting means 88.

Slidably connected with the frame end plates 43 for lateral adjustmentrelative to the board are a pair of slide members to which are pivotallyconnected by pivot pins 92 an impregnant supply channel member 94 and asuction channel member 96, respectively, that extend longitudinallyadjacent opposite edges of the board. The channel members are providedwith lateral extensions 94a, 96a that are received in correspondingguide slots contained in the forward and rear edges of the frame endplates 43, said lateral extensions serving with the slots to support thechannel members for limited pivotal movement in a horizontal plane abouttheir respective pivot axes 92. In order to laterally adjust the channelmembers relative to the frame to accommodate corrugated board of varyingwidths, and to control the pivotal orientation of the channel membersabout their pivot axes, there aresecured to the frame cross supports 50athat extend between the runs of the lower endless belt 66 four hydraulicpiston-cylinder motors 97, 98, 100 and 102. Upon the simultaneousextension and contraction of the hydraulic motor means, the spacingdistance between the channel members may be increased anddecreased,respectively.

Referring now to FIG. 7-11,- each of the impregnating supply and suctionchannel members comprises a plurality of longitudinal sections connectedat adjacent ends by male pin and female recess means 106 (FIG. 11),andby rod means 108 extending longitudinally therethrough for boltingthe sections together to form arigid assemblage. The impregnant supplychannel 94 includes a first series of longitudinally spaced outlets 110(FIG. 8) to which the impregnant of desiredconsistency is supplied fromsource 32 via heated conduits 112,

114 and 116 containing flow regulating means 120, 122 and 124,respectively, whereby the impregnant material is supplied adjacent oneedge of the board. Furthermore, the impregnant supply channel includes asecond series of longitudinally spaced outlets 130 (FIG. 9) to which hotair is supplied from source 132 via conduits 134, 136, 138, 140 and 142containing flow regulating means 144, 146, 148, 150 and 152,

v respectively. Finally, hot air is also supplied to the outlets 1 ofthe impregnating channel sections via conduits 156, 158 and 160containing flow regulating means 162, 164 and 166,

respectively. Similarly, the suction channel member 96 which defines thesuction chamber 96c having a vertical rear wall 96a includes a series oflongitudinally spaced inlets 170 FIG. 10) that are connected with thesuction means 36 via conduits 174, 176, 178, 180', 182 and 184containing flow regulator means 186, 188, 190, 19 2, 194 and 196,respectively. Passages 198 and 200 extend longitudinally through thesupply and suction channels, respectively, for conducting a heatingfluid such as steam through the sections to maintain the impregnatingmaterial in a heated condition. In the alternative, the channels may beheated by electrical heating means.

Referring now more particularly to FIG. 8, the impregnant supplyingsection 94a has aninlet 116a communicating with the conduit 116 tosupply the-impregnant (for example, hot

wax in liquid or atomized form) to the outlet 110 via the rotatable flowcontrol member 210 containing the transverse metering slot 212. Asshown-in FIGS. 11 and 12, the control member 210 has an operating handle214 that extends radially through a cover plate 216 to permit manualadjustment of the meterin position of the control member, and controlover the quantity of impregnant admitted to the flutes. The impregnantis directed downwardly adjacent the feed lip 218, whereupon theimpregnant is mixed with the air supplied via the converging passage 220to produce, according to one embodiment, an impregnant/air dispersion.This hot air is withdrawn by suction fromthe air box section 94b of thechannel member as shown in FIG. 8. In a similar manner, the air iswithdrawn by suction from the air box chamber 940 ofthe impregnatingchannel section 94d as shown in FIG. 9. In order to seal the ends of theflutes that extend within each channel member, there is provided alongitudinally extending seal strip 224 that is biased downwardly intoengagement with the upper surface of the board by the spring means 226,the edge of the board being supported by a layer 228 of syntheticplastic material. If desired, the seal means may-include means (such asrubber lips or brushes) at the ends of the channel members to further,seal the ends of the .flutes from atmosphere. As will be apparent froma comparison of FIGS. 9 and 10, the suction channel sections areidentical to the air section 940 and 94d of the impregnation channel 94.In the case where the seal strip comprises a sheet of thin material,such as foil, it will automatically be sucked toward sealing engagementwith the surface of the board, whereby the necessity of spring meansequivalent to thespring means 226 is avoided.-

In order to prevent a greater concentration of the impregnant adjacentthe supply end of the flutes than the suction end (which would normallyoccur because of the increase in speed of the impregnant as it movestoward the suction means), the various flow control devices in theimpregnant, hot air and suction conduits, respectively, are adjusted asnecessary. Thus, at the impregnant supply side of the board, the hot airis first introduced in the flutes via conduit 134 and valve means 144,whereupon impregnant is successively introduced into the flutes viaheated conduits 156, 158 and 160 as regulated by the adjusting means162, 164 and 168. By appropriate regulation of these control means, theproper successive impregnant charges are introduced into the flutes, andthe subsequent application of hot air via the conduits 136, 138, 140 and142 as controlledby the valves 146, 148, 150 and 152 cooperates with thevacuum means .in drawing the impregnant through the flutes. Forexample,as the speed of the material increases, the air supply may bereduced by appropriate controlof the valve means to slow down theimpregnant material as it traverses the board. Similarly, at the vacuumside, it may be desirable to have the first group of regulators 186, 188and 190 in a fully open condition to effect maximum suction effect,while the successive controllers 192, 194 and 196 may be in a partiallythrottled condition to produce a reduced suction effect. Of course, theadjustment of the flow regulators for the hot air, suction andimpregnation conduits would vary in accordance with the specificimpregnant utilized, the linear speed, of the board, whether the boardis of the single or double wall type, the width of the 7 board, thedimensions of the flutes, and so forth. The versatili' piston-cylindermotor means 224 and 226,

ty of impregnation afforded by the apparatus of the present invention,the possibility of impregnating the board at the high productionvelocity during standard production process, and the adaptability of theimpregnation equipment for installation on existing corrugator systemsare prime advantages afforded by the improved apparatus. Moreover, theapparatus affords such accurate control that no more wax is applied tothe board than is necessary to effect the desired degree ofimpregnation. As contrasted to the known impregnatingprocedures of thepatented prior art, any selected degree of saturation of the board maybe achieved.

As shown in FIG. 7, the channel members are connected for pivotalmovement about axes 92, whereby an additional control is presented forpreventing wandering of the board. If desired, conventional edge sensingmeans (not shown) may be provided for operating the hydraulic pistoncylinder motors 97, 98, and 102 to accurately control the positions andorientations of the channel members relativeto the board. Referring nowto FIG. '13, a modification of the separator apparatus is disclosed inwhich the channel members are mounted for movement independently of theframe, the impregnant supply channel being combined with heat exchangermeans to form a unit 220, and the suction channel member being combinedwith the separator unit 222. These units may be mounted on rollers forlateral displacement of the board by respectively. The upper and lowerendless belts 228; and 230 are carried by the frame 232 for retainingthe board against lateral displacement during transport through theimpregnating station. By combining the suction channel with theseparator means, improved suction is achieved and the temperature of thewax in the separator may be more readily controlled for separation fromthe air prior to entry in the vacuum pump means. Similarly, by combiningthe impregnant supply means with the heat exchanger, a more uniformtemperature of the wax may be effected.

Referring now to FIG. 14, there is shown diagrammatically a modificationof the impregnant supply means for supplying adjacent the ends of theflutes a curtain of a wax/air dispersion from inlet 240 through outlet242 via the flow regulator 244. When the board 16 is adjacent thetransverse outlet 246, the vacuum established in the flutes by thesuction means causes the wax/air curtain to be drawn into the flutestogether with the hot air supplied via passage 248. Thisembodimentoffers the advantage that the wax/air curtain may be continuouslyrecycled, and will be drawn through the passage 246 only when the boardis present, thereby affording an automatic cutoff.

In FIG. 15, there is illustrated another modification of the impregnantsupply means, which modification is particularly suitable for use in theintegral heat exchanger supply means of FIG. 13. In this embodiment, thehot wax is supplied to turbulence mixing chamber 260 via the heatexchanger means 262 of the unit 220 via air-less wax spray meansincluding dispersion chamber 264 and the spray nozzle 266. Hot air issupplied to the turbulence mixing chamber in converging jets viaconduits 268 and 270 containing control valves 272 and 274,respectively. The wax and hot air is thoroughly mixed owing to theturbulence in the chamber 260, and is drawn by suction from the chambervia outlet passage 276 by the vacuum established in the flutes of thecorrugated board 278 travelling continuously thereby. In order toregulate the mixing of the air with the wax, the nozzle means 266 isaxially displaceable (by conventional adjusting means, not shown)between the illustrated left-hand position and a right-hand positionadjacent the inlet orifice of passage 276. Drain passage 280 is providedin communication with the bottom of the chamber 260 to drain the waxcondensate therefrom. As shown in the modification illustrateddiagrammatically in cross-section in FIG. 16, the turbulence mixingchamber 286 containing the wax spray nozzle 288 may be concentricallyjacketed to define chambers 290, 292 to which a hot fluid (such as steamor air) is supplied to maintain the wax-air mixture at a desirably hightemperature. In the case one of the fluids is hot air, it may bedischarged into the chamber via orifices so arranged as to enhance theturbulence mixing effect.

In certain instances, the provision of the upper endless belt may beomitted. For example, in the case of corrugated board that is to becoated with a material such as flexographic white ink, the coating layeritself serves as an impervious covering that is drawn toward the bottombelt by the vacuum established in the flutes.

In order to retain the gluability and printability surfacecharacteristics of the board, it may be desirable to apply (by spraying,sponging or the like) to at least one exposed face of the board prior toimpregnation a temporary coating of a liquid material, such as water.

Finally, by filling the flutes with a mixture of asphalt and wax, a foamthat will form a rigid mass, or certain resins, the structural strengthof the board is increased to such an extent that the impregnated boardmay be used as an interior or exterior construction material.

While in accordance with the provisions of the Patent Statutes thepreferred form and embodiments of the invention have been illustratedand described, it will be apparent that various modifications andchanges may be made without deviating from the inventive concept.

What is claimed is:

I. Apparatus for impregnating horizontally arranged corrugated boardcontinuously supplied by corrugator apparatus at a uniform initiallinear velocity, said board including a serpentine fibrous intermediatelayer cooperating with at least one fibrous outer layer to define asuccession of transversely extending flutes, comprising a. stationaryimpregnant supply means for supplying fluid impregnating materialadjacent one longitudinal edge of said board;

b. stationary suction means arranged adjacent the other longitudinaledge of said board for establishing a vacuum in said flutes to draw theimpregnating material therethrough; and

c. retaining means for preventing lateral displacement of said board inthe direction of said suction means during passage of said board betweensaid supply means and said suction means, said retaining meansincluding 1. a stationary frame extending transversely of the boardbetween said impregnant supply means and said suction means; and

2. clamping means connected with said frame and operable in response tothe vacuum established in the flutes for clamping said board againstlateral movement relative to said frame, said clamping means includinga. longitudinally extending endless belt means adjacent at least one ofthe upper and lower surfaces of the board, said endless belt meanshaving such a width relative to the width of the board that the belt issucked by the vacuum in the flutes into clamping engagement with theboard; and

b. drive means for driving the endless belt means at a velocity at leastas great as said initial linear velocity.

2. Apparatus for impregnating longitudinally traveling corrugated boardhaving a serpentine fibrous intermediate layer 5 defining with at leastone outer layer a succession of transversely extending flutes,comprising a. corrugator apparatus for forming roll paper intocorrugated board and for conveying the board at a uniform initial linearvelocity; b. stationary impregnant supply means for supplyingimpregnating material adjacent one longitudinal edge of said board; c.stationary suction means arranged adjacent the other longitudinal edgeof said board for establishing a vacuum in said flutes to draw theimpregnating material therethrough; d. retaining means for preventinglateral displacement of said board in the direction of said suctionmeans during passage of said board between said supply means and saidsuction means, said retaining means including 1. a stationary frameextending transversely of the board between said impregnant supply meansand said suction means; and

2. clamping means connected with said frame and operable in response tothe vacuum established in the flutes for clamping said board againstlateral movement relative to said frame, said clamping means includinglongitudinally extending endless belt means adjacent at least one of theupper and lower surfaces of the board, said endless belt means havingsuch a width relative to the width of the board that the belt is suckedby the vacuum in the flutes into clamping engagement with the board;

e. stationary means for longitudinally scoring and slitting theimpregnated board into sections;

f. rotary cut-off means for severing the sections into given lengths,

g. and means for driving said endless belt means and said rotary cut-offmeans in synchronism with said board conveying means.

3. Apparatus as defined in claim 2, and further including support meansfor alternately supporting said frame at operative and inoperativepositions, respectively, relative to said corrugator conveying means andsaid scoring and slitting means.

4. Apparatus for impregnating continuously traveling horizontallyarranged corrugated board including a serpentine fibrous intermediatelayer cooperating with at least one fibrous outer layer todefine asuccession of transversely extending flutes, comprising a. stationaryimpregnant supply means for supplying fluid impregnating materialadjacent one longitudinal edge of said board;

b; stationary suction means arranged adjacent the other longitudinaledge of said board for establishing a vacuum in said flutes to draw theimpregnating material therethrough; and

c. retaining means for preventing lateral displacement of said board inthe direction of said suction means during passage of said board betweensaid supply means and said suction means, said retaining meansincluding 1. a stationary frame extending transversely of the boardbetween said impregnant supply means and said suction means; and

2. clamping means Connected with said frame and operable in responseto'the vacuum established in the flutes for clamping said board againstlateral movement relative to said frame; and

d. means for adjusting each of said impregnant supply means and saidsuction means laterally of said corrugated board -to accommodatedifferent widths of corrugated board stock.-

5. Apparatus for impregnating continuously traveling horizontallyarranged corrugated board including a serpentine fibrous intermediatelayer cooperating with at least one fibrous outer layer to define asuccession of transversely extending flutes, comprising a. stationaryimpregnant supply means for supplying fluid impregnating materialadjacent one longitudinal edge of said board, said impregnant supplymeans including 1. a source of fluid impregnating material;

2. a channel member extending longitudinally adjacent said one boardedge, said channel member including a first series of longitudinallyspaced first outlets arranged for communication with one end of theboard flutes; and

3. a plurality of conduit means each containing adjustable flowregulating means for connecting said first outlets with said source,respectively; stationary suction means arranged adjacent the otherlongitudinal edge of said board for establishing a vacuum in said flutesto draw the impregnating material therethrough; and retaining means forpreventing lateral displacement of said board in the direction of saidsuction means during passage of said board between said supply means andsaid suction means, said retaining means including 1. a stationary frameextending transversely of the board between said impregnant supply meansand said suction means; and

2. clamping means connected with said frame and operable in response tothe vacuum established in the flutes for clamping said boardagainstlateral movement relative to said frame.

6. Apparatus for impregnating longitudinally traveling horizontallyarranged corrugated board having a serpentine fibrous intermediate layerdefining with at least one planar fibrous outer layer a succession oftransversely extending flutes, comprising i a. a frame;

b. stationary suction means connected with said frame for defining asuction chamber having a rear wall portion adjacent and spaced from onelongitudinal edge of said board to establish a vacuum in said flutes;

c. stationary impregnant supply means connected with said frame directlyopposite said suction means for supplying fluid impregnating materialadjacent the other longitudinal edge of said board, whereby saidfluidimpregnating material is drawn by suction through the flutes toimpregnate at least the internal portion of the board; and

cl. retaining means for preventing lateral displacement of said board inthe direction of said suction means during passage of said board betweensaid supply means and said suction'means, said retaining meanscomprising longitudinally extending horizontal endless belt meansadjacent at least one of the upper and lower surfaces of the board, saidendless belt means having such a width relative to the width of theboard that the beltis sucked by the vacuum in the flutes into clampingengagement with the board.

7. Apparatus as defined in claim 6, wherein the width of said endlessbelt means is less than the width of the board.

8. Apparatus as defined in claim 6, wherein said endless belt meanscomprises upper and lower endless belts having longitudinal runsadjacent the upper and lower surfaces of said board, respectively.

9. Apparatus as defined in claim 8, wherein at least one of said beltsis impervious.

10. Apparatus as defined in claim 4, wherein each of said lateraladjustment means includes guide means slidably connected for lateralmovement relative to said frame, and hydraulicpiston-cylinder means forlaterally displacing said guide means relative to said frame.

11. Apparatus as defined in claim 10, wherein each of said impregnatingsupply means and said suction means includes a channel member extending.longitudinally adjacent opposite edges of the corrugated board,respectively; 7

and further including pivot means connecting each of said channelmembers with the corresponding guide member, respectively, for pivotalmovement about an axis normal to the plane of the corrugated board.

12. Apparatus as defined in claim 5, wherein said impregnant supplychannel member includessubsequent to said first series of outlets asecond series of longitudinally spaced second outlets, and furtherincluding a plurality of conduit means each containing adjustableflowregulating means for supplying hot air to said second outlets,respectively.

13. Apparatus as defined in claim 12, wherein said suction meansincludes a channel member extending longitudinally adjacent the oppositeedge of the cardboard, said suction channel member including a series oflongitudinally spaced inlets arranged for communication with the otherend of the board flutes;

said suction means including also a vacuum source, and a plurality ofconduits each containing adjustable flow regulating means for connectingsaid channel inlets with said vacuum source.

14. Apparatus as defined in claim 13, wherein at least one of saidchannel members comprises a longitudinal series of sections, and meansconnecting said sections to form a rigid assembly.

15. Apparatus as defined in claim 14, wherein said channel sectionconnecting means includes pin means extending longitudinally from oneend of one section, the adjacent end of the next section containingcorresponding recess means for receiving said pin means.

16. Apparatus as defined in claim 13, and further wherein each of saidchannel members includes seal means for sealing the ends of the flutesfrom the ambient atmosphere during passage of said flutes through theimpregnation station.

17. Apparatus as defined in claim 13, and further including means forheating at least one of said channel members.

18. Apparatus as defined in claim 6, wherein said impregnant supplymeans includes means for mixing together controlled quantities of animpregnant and a transporting gaseous fluid.

19. Apparatus as defined in claim 18, wherein said impregnant supplymeans includes means defining a turbulence mixing chamber, spray nozzlemeans for introducing the impregnant into said chamber, and means forintroducing hot air into said chamber, said chamber having an outletadjacent one longitudinal edge of the board for supplying theimpregnant/air mixture to the flutes.

20. Apparatus as defined in claim 19, wherein said spray nozzle means isaxially adjustable relative to said chamber outlet.

21. Apparatus for impregnating longitudinally travelling horizontallyarranged corrugated board having a serpentine fibrous intermediate layercooperating with at least one planar fibrous outer layer to define asuccession of transversely extending flutes, comprising a. a frame;

b. stationary suction means connected with said frame adjacent onelongitudinal edge of said board to establish a vacuum in the flutesopposite thereto, said suction means including a suction channel memberdefining a longitudinally extending suction chamber partially receivingthe adjacent edge portion of said board, said suction chamber having arear wall portion adjacent and spaced from the adjacent edge extremityof said board;

d. retaining means for preventing lateral displacement of said board inthe direction of said suction means during passage of said board betweensaid supply means and said suction means.

1. Apparatus for impregnating horizontally arranged corrugated boardcontinuously supplied by corrugator apparatus at a uniform initiallinear velocity, said board including a serpentine fibrous intermediatelayer cooperating with at least one fibrous outer layer to define asuccession of transversely extending flutes, comprising a. stationaryimpregnant supply means for supplying fluid impregnating materialadjacent one longitudinal edge of said board; b. stationary suctionmeans arranged adjacent the other longitudinal edge of said board forestablishing a vacuum in said flutes to draw the impregnating materialtherethrough; and c. retaining means for preventing lateral displacementof said board in the direction of said suction means during passage ofsaid board between said supply means and said suction means, saidretaining means including
 1. a stationary frame extending transverselyof the board between said impregnant supply means and said suctionmeans; and
 2. clamping means connected with said frame and operable inresponse to the vacuum established in the flutes for clamping said boardagainst lateral movement relative to said frame, said clamping meansincluding a. longitudinally extending endless belt means adjacent atleast one of the upper and lower surfaces of the board, said endlessbelt means having such a width relative to the width of the board thatthe belt is sucked by the vacuum in the flutes into clamping engagementwith the board; and b. drive means for driving the endless belt means ata velocity at least as great as said initial linear velocity. 2.clamping means connected with said frame and operable in response to thevacuum established in the flutes for clamping said board against lateralmovement relative to said frame, said clamping means including a.longitudinally extending endless belt means adjacent at least one of theupper and lower surfaces of the board, said endless belt means havingsuch a width relative to the width of the board that the belt is suckedby the vacuum in the flutes into clamping engagement with the board; andb. drive means for driving the endless belt means at a velocity at leastas great as said initial linear velocity.
 2. clamping means connectedwith said frame and operable in response to the vacuum established inthe flutes for clamping said board against lateral movement relative tosaid frame; and d. means for adjusting each of said impregnant supplymeans and said suction means laterally of said corrugated board toaccommodate different widths of corrugated board stock.
 2. a channelmember extending longitudinally adjacent said one board edge, saidchannel member including a first series of longitudinally spaced firstoutlets arranged for communication with one end of the board flutes; and2. clamping means connected with said frame and operable in response tothe vacuum established in the flutes for clamping said board againstlateral movement relative to said frame.
 2. Apparatus for impregnatinglongitudinally traveling corrugated board having a serpentine fibrousintermediate layer defining with at least one outer layer a successionof transversely extending flutes, comprising a. corrugator apparatus forforming roll paper into corrugated board and for conveying the board ata uniform initial linear velocity; b. stationary impregnant supply meansfor supplying impregnating material adjacent one longitudinal edge ofsaid board; c. stationary suction means arranged adjacent the otherlongitudinal edge of said board for establishing a vacuum in said flutesto draw the impregnating material therethrough; d. retaining means forpreventing lateral displacement of said board in the direction of saidsuction means during passage of said board between said supply means andsaid suction means, said retaining means including
 2. clamping meansconnected with said frame and operable in response to the vacuumestablished in the flutes for clamping said board against lateralmovement relative to said frame, said clamping means includinglongitudinally extending endless belt means adjacent at least one of theupper and lower surfaces of the board, said endless belt means havingsuch a width relative to the width of the board that the belt is suckedby the vacuum in the flutes into clamping engagement with the board; e.stationary means for longitudinally scoring and slitting the impregnatedboard into sections; f. rotary cut-off means for severing the sectionsinto given lengths; g. and means for driving said endless belt means andsaid rotary cut-off means in synchronism with said board conveyingmeans.
 3. Apparatus as defined in claim 2, and further including supportmeans for alternately supporting said frame at operative and inoperativepositions, respectively, relative to said corrugator conveying means andsaid scoring and slitting means.
 3. a plurality of conduit means eachcontaining adjustable flow regulating means for connecting said firstoutlets with said source, respectively; b. stationary suction meansarranged adjacent the other longitudinal edge of said board forestablishing a vacuum in said flutes to draw the impregnating materialtherethrough; and c. retaining means for preventing lateral displacementof said board in the direction of said suction means during passage ofsaid board between said supply means and said suction means, saidretaining means including
 4. Apparatus for impregnating continuouslytraveling horizontally arranged corrugated board including a serpentinefibrous intermediate layer cooperating with at least one fibrous outerlayer to define a succession of transversely extending flutes,comprising a. stationary impregnant supply means for supplying fluidimpregnating material adjacent one longitudinal edge of said board; b.stationary suction means arranged adjacent the other longitudinal edgeof said board for establishing a vacuum in said flutes to draw theimpregnating material therethrough; and c. retaining means forpreventing lateral displacement of said board in the direction of saidsuction means during passage of said board between said supply means andsaid suction means, said retaining means including
 5. Apparatus forimpregnating continuously traveling horizontally arranged corrugatedboard including a serpentine fibrous intermediate layer cooperating withat least one fibrous outer layer to define a succession of transverselyextending flutes, comprising a. staTionary impregnant supply means forsupplying fluid impregnating material adjacent one longitudinal edge ofsaid board, said impregnant supply means including
 6. Apparatus forimpregnating longitudinally traveling horizontally arranged corrugatedboard having a serpentine fibrous intermediate layer defining with atleast one planar fibrous outer layer a succession of transverselyextending flutes, comprising a. a frame; b. stationary suction meansconnected with said frame for defining a suction chamber having a rearwall portion adjacent and spaced from one longitudinal edge of saidboard to establish a vacuum in said flutes; c. stationary impregnantsupply means connected with said frame directly opposite said suctionmeans for supplying fluid impregnating material adjacent the otherlongitudinal edge of said board, whereby said fluid impregnatingmaterial is drawn by suction through the flutes to impregnate at leastthe internal portion of the board; and d. retaining means for preventinglateral displacement of said board in the direction of said suctionmeans during passage of said board between said supply means and saidsuction means, said retaining means comprising longitudinally extendinghorizontal endless belt means adjacent at least one of the upper andlower surfaces of the board, said endless belt means having such a widthrelative to the width of the board that the belt is sucked by the vacuumin the flutes into clamping engagement with the board.
 7. Apparatus asdefined in claim 6, wherein the width of said endless belt means is lessthan the width of the board.
 8. Apparatus as defined in claim 6, whereinsaid endless belt means comprises upper and lower endless belts havinglongitudinal runs adjacent the upper and lower surfaces of said board,respectively.
 9. Apparatus as defined in claim 8, wherein at least oneof said belts is impervious.
 10. Apparatus as defined in claim 4,wherein each of said lateral adjustment means includes guide meansslidably connected for lateral movement relative to said frame, andhydraulic piston-cylinder means for laterally displacing said guidemeans relative to said frame.
 11. Apparatus as defined in claim 10,wherein each of said impregnating supply means and said suction meansincludes a channel member extending longitudinally adjacent oppositeedges of the corrugated board, respectively; and further including pivotmeans connecting each of said channel members with the correspondingguide member, respectively, for pivotal movement about an axis normal tothe plane of the corrugated board.
 12. Apparatus as defined in claim 5,wherein said impregnant supply channel member includes subsequent tosaid first series of outlets a second series of longitudinally spacedsecond outlets, and further including a plUrality of conduit means eachcontaining adjustable flow regulating means for supplying hot air tosaid second outlets, respectively.
 13. Apparatus as defined in claim 12,wherein said suction means includes a channel member extendinglongitudinally adjacent the opposite edge of the cardboard, said suctionchannel member including a series of longitudinally spaced inletsarranged for communication with the other end of the board flutes; saidsuction means including also a vacuum source, and a plurality ofconduits each containing adjustable flow regulating means for connectingsaid channel inlets with said vacuum source.
 14. Apparatus as defined inclaim 13, wherein at least one of said channel members comprises alongitudinal series of sections, and means connecting said sections toform a rigid assembly.
 15. Apparatus as defined in claim 14, whereinsaid channel section connecting means includes pin means extendinglongitudinally from one end of one section, the adjacent end of the nextsection containing corresponding recess means for receiving said pinmeans.
 16. Apparatus as defined in claim 13, and further wherein each ofsaid channel members includes seal means for sealing the ends of theflutes from the ambient atmosphere during passage of said flutes throughthe impregnation station.
 17. Apparatus as defined in claim 13, andfurther including means for heating at least one of said channelmembers.
 18. Apparatus as defined in claim 6, wherein said impregnantsupply means includes means for mixing together controlled quantities ofan impregnant and a transporting gaseous fluid.
 19. Apparatus as definedin claim 18, wherein said impregnant supply means includes meansdefining a turbulence mixing chamber, spray nozzle means for introducingthe impregnant into said chamber, and means for introducing hot air intosaid chamber, said chamber having an outlet adjacent one longitudinaledge of the board for supplying the impregnant/air mixture to theflutes.
 20. Apparatus as defined in claim 19, wherein said spray nozzlemeans is axially adjustable relative to said chamber outlet. 21.Apparatus for impregnating longitudinally travelling horizontallyarranged corrugated board having a serpentine fibrous intermediate layercooperating with at least one planar fibrous outer layer to define asuccession of transversely extending flutes, comprising a. a frame; b.stationary suction means connected with said frame adjacent onelongitudinal edge of said board to establish a vacuum in the flutesopposite thereto, said suction means including a suction channel memberdefining a longitudinally extending suction chamber partially receivingthe adjacent edge portion of said board, said suction chamber having arear wall portion adjacent and spaced from the adjacent edge extremityof said board; c. stationary impregnant supply means connected with saidframe directly opposite said suction means for supplying fluidimpregnating material adjacent the other longitudinal edge of saidboard, whereby said fluid impregnating material is drawn by suctionthrough the flutes to impregnate at least the internal portion of theboard; and d. retaining means for preventing lateral displacement ofsaid board in the direction of said suction means during passage of saidboard between said supply means and said suction means.